The present invention relates to a device for limiting the maximum radiation intensity of a radiation source, in particular a laser, as well as a device for coupling high radiation intensity of a radiation source, in particular a pulse laser, to an optic fiber.
Gray filters with different yet definite transparency values are, for example, known for limiting the radiation intensity of radiation sources. In glasses, so-called light-adjusting ("self-tinting") glasses are known, the transparency of which diminishes with increasing intensity of sun light.
The known devices are not suited for limiting the radiation intensity of a radiation source to a certain maximum but allowing lower ones to pass unhindered. Such devices react much too slowly to intensity peaks, so that material damage could occur, especially when lasers are employed as radiation sources. Especially when pulse lasers are used, such excessive intensity increases can originate through spatial (hot spots) and temporal modulation of the laser pulses.